(1) Field of Invention
The present invention relates to a series of novel silicone phosphate esters which mitigate eye and skin irritation when used in synergistic combinations with fatty alcohol sulfates and fatty alcohol ether sulfates. The compounds useful in to form synergistic combinations with fatty alcohol sulfates and fatty alcohol ether sulfates are the topic of U.S. Pat. No. 5,070,171 issued to O'Lenick, Jr. and U.S. Pat. No. 5,149,762 likewise issued to O'Lenick, Jr. which are incorporated herein by reference. These compounds are referred to in this specification as silicone phosphate esters. They are items of commerce and are manufactured by Siltech Inc. of Norcross Ga., to whom the above patents are assigned.
The compounds useful in preparing the synergistic blends of the present invention are fatty alcohol sulfates or fatty alcohol ether sulfates and silicone phosphate esters. The silicone phosphate esters are items of commerce and are prepared by the phosphation of a pendant hydroxyl group which is present on a silicone polymer.
We have surprisingly learned that if the silicone phosphate esters described in the above mentioned patents are mixed with fatty alcohol sulfates or fatty alcohol ether sulfates prior to contact with the eye and skin that the irritation values of the mixture are reduced by a factor of three. Application of the silicone phosphate ester to the skin or eye either before or immediately after the application of the fatty alcohol sulfate or fatty alcohol ether sulfate does not appreciably reduce the irritation values encountered. This is strong evidence for the formation of a complex which provides the protection. Generally, complexes form when anionic and cationic compounds are mixed. This is because of the opposite charges on the molecules. Generally, these complexes lose their surfactant properties such as foam and wetting. These complexes also do not mitigate irritation. Surprisingly, we have learned that there is a complex formed between the anionic fatty alcohol sulfate or fatty alcohol ether sulfate and the anionic silicone phosphate ester which mitigates irritation.
(2) Object of the Invention
It is the object of the present invention to provide a complex which mitigates irritation of fatty alcohol sulfates or fatty alcohol ether sulfates to the eyes and skin by incorporating a series of novel phosphated silicone polymers. The ratio of phosphate to sulfate can range from 1:1 to 0.01 to 1.
It is another objective of the current invention to provide a process for treating the hair and skin with the complex between the fatty alcohol sulfate or ether sulfate and the phosphated silicone polymer. The process comprises (1) formation of the complex by mixing together silicone phosphate ester and fatty alcohol sulfate or fatty alcohol ether sulfate and silicone phosphate ester, (2) contacting the hair or skin with an effective cleansing amount of the complex and (3) removing excess complex by rinsing with water. The ratio of phosphate to sulfate can range from 1:1 to 0.01 to 1.
(3) Description of the Arts and Practices
Fatty alcohol sulfates and fatty alcohol ether sulfates are a class of anionic detergents which are used very commonly in shampoo, skin cleanser and other applications which require detergency properties. These materials while outstanding detergents are quite irritating to skin and eyes. This is due in part to the fact that these materials de-fat the skin and eyes. That is they remove the naturally occurring fatty materials found in the normal hair and skin and leave the skin or eyes in a clean albeit irritated state.
The inclusion of ethylene oxide into the sulfate has a marginal effect upon irritation, reducing it somewhat. This reduction is obtained at the expense of cleansing properties. It was not until the present invention that it was realized that formation of a fatty alcohol sulfate or fatty alcohol ether sulfate and silicone phosphate ester complex effectively reduced irritation and did not adversely affect the performance of the detergent properties of the sulfate.
U.S. Pat. No. 5,070,171 issued to O'Lenick, Jr. and U.S. Pat. No. 5,149,762 likewise issued to O'Lenick, Jr. disclose the technology used to prepare the silicone phosphate esters useful as one ingredient in preparing the complex of the present invention.